I’m generally a supporter of of slow or stopped traffic. But I’ve always wondered how truly safe the practice is. We now have some insight as a French study concluded that lane splitting caused a 12 percent increase in motorcycle crashes in the areas the study was conducted in.

This news comes from the (FEMA). The study was conducted in 11 French departments — the French equivalent of a county — over a period of five years. The Centre for Studies and Expertise on Risks, Environment, Mobility and Planning (CEREMA) was in charge of assessing the study while the (French Federation of Angry Bikers, according to Google) helped set up lane splitting guidelines.

The end result? The shows that over the five year period, motorcycle accidents increased by 12 percent in the 11 departments while accidents decreased by 10 percent on roads outside of the testing area.

But it’s not all bad news. The report also shows that the study successfully spread lane-splitting awareness to car drivers, especially newly trained drivers. Drivers also took well to the splitting of the motorcycles, too.

Eric Thiollier, board member of FFMC, the impact was positive, even if the results weren’t as expected:

The behaviour and the safety records improved significantly during the five year period of the experiment, showing that setting rules had a positive impact, although not enough to be satisfying. The increase in accidents could also be linked to the fact that more powered two-wheelers were lane-splitting.

Thankfully, it appears the organizers of the first study are gearing up for a second study to see how splitting could be made safer in the region.

A 2014 UC Berkeley study concluded that motorcycles that lane split are less likely to be rear-ended by a car but are more likely to rear-end a car, reports . Speed differential between a splitting motorcycle and car traffic turned out to be a big factor determining danger. It suggested that riders who split in a slow and safe manner are in no more danger than they usually are otherwise.

Lane splitting is illegal here in Illinois. Despite that, I see a lot of motorcycles lane splitting, anyway. Seeing a splitting motorcycle almost get clobbered by a lane-changing car is a frequent occurrence during the summer. Still, I believe lane splitting can be beneficial. After all, motorcycles don’t need to be stuck in the same traffic jams as cars. I think a combination of safe splitting practices, like maintaining low-speeds, as well as car driver education would be a big help.